Scott Manley - 2025-09-02
The Electric Arc Shock Tunnel (EAST) at NASA Ames can generate hypervelocity shockwaves in test atmospheres to understand what happens during atmospheric entry. This system uses a capacitor bank that stored up to 1.25MegaJoules to drive a shockwave in a test gas then observe the light emitted. This is essential to determining the radiative heating that will be experienced during atmospheric entry, and the facility at NASA Ames is the only one in the world that can even get close to the conditions experienced by probes to the gas giants. Follow me on Twitter for more updates: https://twitter.com/DJSnM I have a discord server where I regularly turn up: https://discord.gg/zStmKbM If you really like what I do you can support me directly through Patreon https://www.patreon.com/scottmanley
When I was working at Aerospatiale in Cannes, we developed the Huygens probe which flew piggyback on US Cassini spacecraft. Aerospatiale got the contract because of its knowledge of reentry bodies of balistic missiles. The female engineer in charge of the modeling of the reentry was in a mission analysis team under my supervision, and she had to deal with uncertainties on Titan's atmosphere composition . One important parameter was the traces of argon in Titan atmosphere which are under 1%, but not well known at the time. She was eager to have more measurements by astronomers, because a tiny fraction of more argon could double the aero-thermodynamic fluxes at reentry. She finally got more accurate data, and her analysis was perfect, Huygens entered Titan atmosphere safely, and sent back the images.
I'd never have guessed that such a small change could make such a huge difference. Is it that argon emits at some particularly unfortunate wavelength or something?
Thank you 😊
Tranz or bio?
@2nostromowym ... Transformer or Decepticon ?😂 Doesn't matter
Huygens is still one of my favourite feats of space exploration ever achieved. Great to hear about the work that went into it.
"Even with a microsecond shutter, the shock would move 7mm between frames"
And that's why the study of how to get data out of physics experiments is such a fascinating area of study for me, it all happens so fast that even computer systems and sensors that are on the bleeding edge of the state of the art leave the scientists still wanting more data at a faster rate. Things in these experiments happen really fast or they don't happen at all, and that makes it very challenging to get the data out even if you know how to briefly manifest a given physical phenomena.
Wouldn’t that be 7 meters? 7km/s divided by 1000, 7m?
There is one video on how they measured the propagation of a nuclear explosion from inside the warhead itself.
I think from Curios Droid.
@blogsfred3187 microsecond is 1/1000000, you are thinking about miliseconds
I love this channel! I just never know what kind of amazing stuff is in store to learn about each time I click. All I do know, there will always be something somewhere Scott says that absolutely blows my mind.
Is there a name for that field of study? How to get the data out of experiments in a valid and sufficient manner?
Love the "Stolen from east facility" @7:35
... and The Fonz sticker at @4:03
you can just imagine the tech guy getting frustrated with his clip-board repeatedly going walkies and finally writing that on the new one!
@15:00 the picture on the tube
Half hoped Electroboom to pop his head up playing with those capacitors or too dangerous for him! Bonkers for 1960.
They do short a tiny wire 😂
I wonder if those cables jump around like a pit of rattle snakes from the magnetic flux?
No
@xephael3485what do you mean no. I would imagine they do
I dont imagine they do, likely just because maintaince would be hell, But for how short of a burst it goes through, it likely doesn't do "much"
I’d be curious to know if that much flux at such a small timeframe would be able to do something. But then again I have no anecdotal experience with 1.25MJ….
Probably some kind of faraday cage system
I like this presentation because it showcases the "hardhat engineering" for facilities that do real work. Unlike posh clean offices of computer screens, here we see a jumbos of cables, plumbing, and other tedious hardware. In order to get real world data, it takes all this stuff and the people knowing how to make it work. We also see there are so many pieces in this food chain if any part is missing, then none of this will work. Of course you can over design the spacecraft but as Scott pointed out if knowing what the margins need to be, then can have more instruments on the spacecraft.
This shows the other element of NASA that is not glamorous, gets very little media coverage. It takes money, time, and patience in order to get real world data. Unfortunately I feel all this at risk with mischief conducted by those at NASA HQ. Then they will wonder why does it take so long to get anything done (as in if we can put a man on the moon, why can't we put a man or a woman on the moon?).
Oh ow. Applied Science guy spotted in the background.
"Today on Applied Science we're making Tholins in a shockwave tunnel, and look at them using my mass spectrometer and electron microscope."
@2:31? I thought that that was Ben the Applied Science guy.
@agenthambo Me too!
Whoa wait, is it really, I wonder?
The engineering behind the rupture disk is massive
The physics of very fast rise time power spikes in buss bars is kinda interesting.
1.25 megajoules is about half of the energy needed to run a typical washing machine cycle, or about one hundredth of the energy stored in a gallon of gasoline!
But releasing it in a tiny fraction of a second gives an enormous energy and power density!
Awesome perspective!
Also about the energy to bring a gallon / 4 liters of water from room temperature to boiling. Not wildly much _energy_, but in the short time of discharge makes it crazy high _power_.
@I_Am_Your_Problem dude, there's something wrong with you, but you'll never know what it is.
I meant energy density and power density. Energy is always conserved.
@I_Am_Your_Problem This comment is a nice reminder that reading comprehension should be prioritized in schools.
"I Am Your Problem" is a bot.
That "FONZ ME HERE" would seem to indicate the specific spot where occasional percussive maintenance is required. Love it.
That capacitor bank is terrifying
Bare buss bars like those always make me quesey. You can't tell if they'll kill you.
The capacity of the capacitors is captivating and categorically capitulating for the charged cathodic quartz crystal components
Look up "ATLAS-I (better known as TRESTLE)"
It's only 30 kilovolts If they made one today they could easily make it a 100 kilovolts
would make a killer coin crusher
I know a person who was involved in experiments like these about 35 years back in a place called LANL. The scientific research has improved due to modern computing technology. The physics will never change.
Los Alamos:) I work there now. I grew up in Albuquerque, some very neat stuff over there.
Waiting for electroboom to comment lol
AAOOOWWW!!
I want to see his diy heated chair upgraded to 1.25MJ capacitor power source. No more waiting in a cold chair.
I love how none of the dangerous components are at any time shielded. Perfect experimental physics.
1:53 Hammilton Morris is in the background disassembling the pipe to get at the xenon.
As someone who has welded that type of equipment, the big stuff is annoying but the small parts are the easiest to make expensive mistakes on, and there are loads of small parts. Cheers Scott, Great as always.
what if it's tiny details ina big part? I remember reading about welding the Saturn V tanks.
Hi, can you please explain what those "dashed" weld seams are about? On the big section at the end of the bigger apparatus (I think called it the wind tunnel section?) the tube manufactured from sheet metal seems to have one continuous weld seam along its length. But everything else attached to the outside is welded to it in a sort of "dashed" or alternating way. Why is it done like this, and how are the contents inside sealed off? Is there a second, but continuous weld seam on the inside of the tube? Cheers
@argh1312 This is for ease of testing of the inner weld and to avoid forming a sealed cavity. One way you can test vacuum chamber for tightness is to to connect a sensitive gas detector (mass-spectrometer) and then evacuate the whole system. You then blow Helium at various points and check when mass-spectrometer shows rise in Helium inside - if it does you found a leak. For this you need the ability to blow Helium at every weld, so they make the outside weld with gaps for easy access. They also make notches in the connector flanges so you can blow Helium there to test the seal.
@argh1312 You cant fully weld the outside in case of trapping air. To create a vacuum, you need to loose all the air inside. If some were trapped within the seam, the vacuum would never be reached as it kept finding a trickle of atmosphere and you would spend forever finding the leak.
@volodya5 Thanks for that explanation! So do I understand correctly that there are inner welds to seal the chamber off, and the outer, gapped welds are for added structural integrity? And yes I was already talking about those flanges. Is it done the same way along the length of the tube as well?
This video highlights the fact that without welders modern society wouldn't exist...
Was very excited to see your "Air Explode Using Electricity" vid. As a young dude exploring the West Coast in 1969 I took a temp job painting walls in a big workspace in a company called Energy Systems, Inc. They were building these exact huge capacitor banks! All I was told was they were aerospace related. Off to one side was a device that looked like a 50's Frankenstein movie prop. It was a tower about 20' tall with big aluminum "donuts", cylinders of plexiglas and a big arc gap in the middle. It was called a "crowbar" and was used to discharge the capacitor banks. Your YouTube was a flashback for me. Love your videos.
@4:00 That fonz picture... a meme before there was memes
It's not a meme. It's a repair manual
big red dot, "fonz me here" text...that is a fully practical label with some humor added
Most interesting......Thank you Scott from an Old combat veteran F-4 Phantom pilot Shoe in my late 80's
Thank you for your service.
Loving the new cadence! Good to have more quality tech content. Thank you.
0:10 open source 😅
Hey! We did the boring, finish turning, and power honing off thus exact tube at our shop! You can see it in our company tour video for fluid tech hydraulics on our big lathe. Super cool project. The finish we were subcontractors did is fantastic, great people. I airways wondered what is actually we used for
An excellent example of how apparently boring science turns out to be very fascinating and important.
Thank you, Scott, for the very detailed and understandable explanations.
4:04 I love those old school "jewel" lights for some reason! Probably from vintage guitar amplifiers that have jewel light power indicators.
Incredible indepth Walk, though ! I think I speak for everybody when I say I would like more of these in-depth videos from Scott!
Post script ; maybe it would be kind of cool and interesting to see him do like a 1 hour DJ.Set just putting it out there
That setup is almost as crazy as one of Photonic Inductions videos.
Damn, Scott Manley, Alpha Phoenix and Ben Krasnow in one place? Nerdvana!
48 km/second is about
107366 mph is about
mach 141
That’s incomprehensible numbers just wow! 😂
At what temperature?
Parker Solar Probe: 430,000 mph.
Using mach without providing the relevant gas parameters is inaccurate. Mach number depends on specific heat capacity (volumetric and barometric), molar mass, and temperature. Especially when we're talking about extreme conditions like this, all of those are highly variable.
My father in law was a shock tube physicist back at Los Alamos in the 50s. He went on to work with underground nuclear tests. I always thought of their crazy tunnels and blast doors as a giant shock tube. Sometimes they actually worked.
Can't wait for AlphaPhoenix and AppliedScience to replicate this in their garages now that they've seen it up close!
I've been waiting for Alpha Phoenix to do this too capacitors have gotten Much more potent in the past 80 years
@Wheezs The 1960s are not 80 years ago from 2025...
Fun to watch this. My granddaughter works for NASA at the Ames facility
Terrific presentation of civil servants doing fascinating research for public good.
A fascinating video about this old Apollo era test-device and to paraphrase Scott, "Fry safe".
Me doing studs capacitive discharge welding today at the shop.
Powerful enough to weld a 1/4-20 steel stud in 0.004 seconds.
Picturing a spacecraft going 60 kps made me do a rough calculation: At that speed, in the duration of a single frame of a movie, it would travel the length of the main span of the Golden Gate Bridge - twice.
That bow wave was so nicely captured
7:35 - I love how his clipboard says "Stolen from east facility" 😁
"Why does NASA use this capacitor for?" Nice.
Great work as always, sir. You'll always get full video watches, a like and a comment from this Clippy. After all, Clippy is here to help. Clippy is also signing up for Patreon.
Ultimate flashbulb.
Here's a scientific paper they made earlier...😂😂 love the cooking show vibes.
All those old school Jewel lights are awesome!
Spectrometry has given us SO much! What an amazing discovery.
Well that was "different" for my "first thing in the morning". Nothing I knew anything about and I am glad I went by your presentation.
The plasma channel is likely actually constrained by the sharp change in current. There's a great video of this being used as a sort of junkyard robot wars style weapon.
Hey! I made a big one of those for nasa a few years back! Super cool to see it in action and what it actually does!
Its wonderful to see all these back room test facilities, thank you, if it weren't for you I would never see this stuff and I really enjoy learning about it.
@scottmanley - 2025-09-02
This video has been available via Early Access to Patreon Supporters - Thanks to the generous people that choose to help me make content like this.
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@gracebromfield9070 - 2025-09-05
Hey Scott, you should pin your comment so it's at the top.
@Stanton_High - 2025-09-06
WHAT does NASA use this capacitor for?
@Voting-does-nothing - 2025-09-06
Hay scott how do you expect people to take you seriously when you follow silly tiktok trends in speech you clown? 🤣🤣🤣
It's better not "bedder" .......... ....
MuppeTTTT
@thespanishinquisition6777 - 2025-09-13
Support what? You not proofreading your thumbnail pictures?
@Anvilshock - 2025-09-13
Beggar.